There is an art in which a right server for delivering right information about content and removable media having a copyright protection function to the recorded content directly perform mutual authentication through a reproducing device capable of record and reproduction on the removable media. In this art system, the encrypted content and the right information had by the server are directly downloaded and saved to the removable media and then, the reproducing device and the removable media perform mutual authentication and while reading the encrypted content from the removable media, the cipher is decoded to thereby reproduce the content.